Monitoring of air pollution in the atmosphere around Oman Liquid Natural Gas (OLNG) plant

This study was basically designed to assess the potential environmental air quality impacts arising from the existing two operational trains at the Oman Liquid Natural Gas (OLNG) plant. The results of the paper contain a baseline survey of the existing environment. The pollutants studied included methane (CH₄), non-methane hydrocarbons (NMHC), carbon monoxide (CO), nitrogen oxides (NO_x), and suspended particulate matters (dust PM 10). Meteorological parameters monitored simultaneously include wind speed and direction, air temperature, and relative humidity. The air quality data were used to determine the diurnal and monthly variations in the pollutants. Description levels of the pollutants with respect to meteorological data were also used in analysis. Moreover, a statistical analysis of the collected data was presented. Generally, the results indicated that the mean concentrations of pollutants were low to cause any significant impact in air quality. The area had no problem in meeting the air quality standards for CO and NO₂. It was also found that there was a random relationship between CO and NMHC, and between NO and NO_x (no apparent correlation). The diurnal peaks of NO_x, NO₂, THC, and NMHC over a 24-h period were observed at around 9:00-10:00 AM (morning peak). For NO, NO₂, and NO _x, another peak was seen at around 5:00 PM (evening peak). Furthermore, the measured concentrations for NO₂, NO_x, and CO were found higher in winter than in summer. The study would help to gain a better understanding of local background levels of air pollutants at the area prior to the construction of new industrial projects, and to prepare action plans for controlling pollution in the area.